Carburetor throttle valve



April 6, 1965 "r. v. DE PALMA 3,176,704

CARBURETOR THROTTLE VALVE Filed Nov. 20, 1961 2 Sheets-Sheet 1 FigureF/gure 8 56 57 54 ii llllifilllllll 5 49 50 IV V E N TOR Ted DePa/ma ATTOR/VEYS April 6, 1965 T. v. DE PALMA 3,176,704

CARBURETOR THROTTLE VALVE Filed Nov. 20, 1961 2 Sheets-Sheet 2 IV VE/VTOR Ted V. DePa/ma A TTOR/VEYS United States Patent 3,176,704 CARBURETORTHROTTLE VALVE Ted V. De Palma, Roselle, lll., assignor to Universal OilProducts Company, Des Plaines, lll., a corporation of Delaware FiledNov. 20, 1961, Ser. No. 153,642 6 Claims. ((1 137-239) This inventionrelates to carburetors and more particularly to an improved carburetorthrottle valve designed to enhance the effectiveness of gasolineadditives in removing or preventing the formation of deposits in andaround the carburetor throttle blade.

Various additives are presently employed in motor fuels. to combat thebuildup of harmful deposits in the carburetor, intake valves and in theengine cylinders proper. These deposits generally comprise dust, grease,road dirt and other air-suspended particulate matter which escapesretention by the carburetor air filter, and/or gum formed by partialoxidation of the fuel; these are counteracted by detergent andantioxidant additives. In

addition to such semipermanent deposits, under certain ambienttemperature and humidity conditions, ice will form in the fuel intakesystem causing stalling until the engine becomes warm; this isconventionally controlled by de-icing agents added to the motor fuel.

One of the most troublesome areas and the one most sensitive to suchdeposits is the carburetor throttle body itself, particularly in andaround the throttle blade or butterfly disc. In order to remove orretard the growth .of solid deposits, it is essential to achieveintimate and thorough contact, at least periodically, between liquidfuel containing the requisite additive and the deposit; in other words,a stream of fuel must be directed against the surface from which it isdesired to remove the deposit. Experimental studies with a transparentthrottle body have shown that with throttle valves of conventionaldesign, effective scrubbing of the throttle body wall is not achieved inwhat is designated herein as the critical deposit area. The criticaldeposit area is defined as that region of the interior surface of thethrottle body which is contiguous to or abuts against the trailing edgeof the butterfly disc when the latter is in its fully closed position.Typically, although not necessarily, the butterfly disc is inclined afew degrees to the horizontal (downdraft type carburetor) even whenfully closed and is therefore rotated through an angle of slightly lessthan 90 in moving from its fully closed to fully opened positions. Thecritical deposit area therefore assumes the form of a circular orslightly elliptical band, centered on a line formed by the intersectionof the plane of the but terfly disc in its fully closed position withthe cylindrical wall of the throttle body, and extending approximately180 around the wall adjacent to or slightly downstream from the axis ofrotation of the disc. Carburetor performance is quickly and adverselyaffected by deposits in this area because of the reduction in an alreadysmall clearance between throttle blade and body; such deposits are evenmore deleterious in the case of a multi-venturi carburetor since theblade-body clearance thereof is considerably smaller than that of asingle barrel carburetor.

The reason why a carburetor throttle valve of conventional design doesnot provide adequate fuel scrubbing of the critical deposit area becomesapparent from a consideration of the geometry of a conventionalcarburetor body. When the butterfly disc is closed, as when the engineis idling, no fuel-air mixture is able to pass around the periphery ofthe disc, the small quantity of fuel which is then required beingadmitted through idle jets located downstream therefrom. When thebutterfly disc is partially open, the liquid phase portion of theinflowing fuel- Eilhflfi i- Patented Apr. 6, 1965 air mixture descendsfrom the main discharge. jet and venturi in the form of a conical spray,impinges upon the inclined fiat upstream surface of the butterfly disc,and is deflected onto the wall of the throttle body at a region which isa substantial distance downstream from the axis of rotation of the discand hence substantially removed from the critical deposit area. Thisresults in adequate scrubbing action on the throttle body wall below thecritical deposit area, but not where it is most needed. In consequencethereof, such deposits as road dirt, gum or ice, as the case may be,which tend to accumulate in the critical deposit area remain relativelyuntouched by the liquid fuel and thus continue to accumulate therebycausing the carburetor to become rapidly detuned.

It is therefore an object of this invention to provide an improvedcarburetor throttlebody assembly wherein the throttle blade or disc isprovided with a fluid-deflecting baffle member arranged to receiveinflowing liquid fuel from the main body of the carburetor and todeflect it against the critical deposit area of the body when thethrottle blade occupies a position intermediate its fully closed andfully opened positions.

A broad embodiment of this invention relates to a carburetor throttlevalve assembly comprising a casing having a fluid inlet opening and afluid outlet opening at opposite ends thereof, a movableflow-obstructing member mounted Within said casing, and afluid-deflecting means connected to said flow-obstructing member andshaped to deflect impinging fluid, when said flow-obstructing member isin a position intermediate its fully closed and fully opened positions,against that region of the interior surface of the casing which isadjacent said flowobstructing member when the latter is in its fullyclosed position.

A more specific embodiment of this invention is directed to a carburetorthrottle valve assembly comprising a casing having a cylindrical boredefining a fluid inlet opening and a fluid outlet opening at oppositeends thereof, a rotatable flow-obstructing disc member mounted withinsaid casing, means for rotating said disc member about an axissubstantially perpendicular to and intersecting the central longitudinalaxis of said casing, and the upstream surface of said disc membercomprising a fluid-deflecting means shaped to deflect impinging fluid,when said disc member is in a position intermediate its fully closed andfully opened positions, against that region of the interior surface ofthe casing which is contiguous to the trailing edge of said disc memberwhen the latter is in its fully closed position.

The term disc or disc member, as employed in the specification andappended claims, is intended to include, but not by way of limitation,plate-type flow obstruction members having elliptical or semi-ellipticalshapes as well as a circular shape.

In accordance with a preferred embodiment of the invention, thefluid-deflecting means is a raised annular ridge or hump formed in theupstream surface of the throttle disc near its trailing edge. The innersurface of the ridge is gradually inclined orsloped toward the center ofthe disc whereby to provide a fluid-deflecting surface which is inclinedmore steeply to the central longitudinal axis of the throttle body thanis the throttle disc proper. The annular ridge may be formed integrallywith the throttle disc as by casting or machining its upstream surfaceor by stamping the disc to its desired shape; the annular ridge may alsobe constructed by a separate piece, as by attaching a beveled ringmember to a standard throttle disc. 'Although deposits tend toaccumulate along most of the arc of the critical deposit area, thedeposits in the central portion thereof, i.e., directly opposite theaxis of rotation of the throttle disc, are the most harmful since therate of change of throttle valvefree area with angular displacement isgreatest at this point. From a practical st'andpoint,'then, it isnecessary to deflect the incoming liquid fuel only against the centralportion of the critical deposit area which should subtend an angle of atleast 20 measured from the center of the throttle disc, and preferablyshould subtend an angle of at least 90". In such case the annular ridgewill subtend an angle of 20 or more, although it may be desirable toextend the ridge 360 around the disc if such construction should besimpler from a manufacturing standpoint.

The several embodiments of the invention and modifications incidentthereto may best be described in conjunction with the accompanyingdrawings which are presented as illustrative of the best mode ofpracticing the invention but not with the intention of unduly limitingits broad scope.

FIGURE 1 is a sectional elevation view of the improved carburetorthrottle. valve of this invention showing the relationship between theridged throttle disc and the throttle body.

FIGURE 2 is a plan view of the throttle disc of FIG- URE 1.

FIGURE 3 is a plan view of an alternate form of throttle disc whereinthe annular ridge extends 360 around the disc.

FIGURE 4 is a sectional elevation view of the throttle disc of FIGURE 3taken along line 44 of FIGURE 3.

FIGURE 5 is a plan view illustrating another embodiment of the throttledisc wherein the annular ridge is formed by stamping the throttle plate.

FIGURE 6 is a sectional elevation view of the throttle disc of FIGURE. 5taken along line 6-6 of FIGURE 5.

FIGURE 7 is a plan view of still another embodiment of the throttle discwherein the annular ridge is formed by attaching a beveled ring segmentto the upstream surface of the disc.

FIGURE 8 is a sectional elevation view of the throttle disc of FIGURE 7taken along line 88 of FIGURE 7.

In FIGURE 1 only so much of a complete single barrel downdraft typecarburetor, e.g., the throttle body, is shown as will facilitate a clearunderstanding of the invention. It is obvious that a complete carburetorwill additionally include a main body and air horn section, floatchamber, idle jets, main jets, and may further include a high speedbypass, accelerator pump, automatic choke and sundry other appurtenanceswell-known to those skilled in the carburetor art, none of which are apart of the instant invention. Although the present discussion isfocused upon a single barrel carburetor, it is understood that theinvention is directly applicable to multi-barrel carburetors as well.The throttle blades hereinbelow described are shown in the drawings ascircular discs but it is to be emphasized that elliptical orsemi-elliptical blades may be substituted therefor without departingfrom the spirit of the invention.

In FIGURE 1 there is shown a casing or throttle body housing 10 havingextending therethrough a cylindrical bore or passageway 11 defined bywall 12. Line 0-0 is the central longitudinal axis of passageway 11 andof casing 10. The upper open end 13 of passageway 11 is the fuel inletopening receiving gasoline and primary air from the main body of thecarburetor, and the lower open end 14 of passageway 11 is the fueloutlet opening which discharges into the intake manifold of the engine.Casing 10 is provided with an upper flange 15 having threaded holes 16therein for bolting the main body of the carburetor thereto, and a lowerflange 17 having bolt holes 18 therethrough for securing casing 10 tothe engine block. A rotatable flow-obstructing disc member or throttleblade 19 is positioned within passageway 11 and is secured to rotaryshaft 20 by means of machine screws 21. Shaft 20 extends horizontallythrough wall 12 and is rotated by suitable linkage connected to theaccelerator pedal. The fully closed position of the disc member isrepresented by plane a-a and its fully opened position by axis 0-o'.

initially flat, thin disc into the desired shape.

The constructional details of .the disc member are shown in FIGURE 1 andin FIGURE 2, to whichlatter figure reference is now also made. The axisof rotation of disc 19 is given by line xx in FIGURE 2. The upstreamsurface of disc 19 is indicated by numeral 22. The leading edge 23 ofdisc 19 is defined as that half of the peripheral edge of disc 19 whichlies upstream from the axis of rotation as the disc is rotated to a moreopen position; the trailing edge 24 of disc 19 is defined as that halfof the peripheral edge of disc 19 which lies downstream from the axis ofrotation as the disc is rotated to a more open position. A raisedannular ridge 25 is formed in the upstream surface 22 of disc 19 nearits trailing edge 24. Ridge 25 is set back a short distance from edge 24so as not to obstruct or hinder the closing of disc 19 as it is movedinto alignment with plane a-a'. The outer surface 26 of the ridge isinclined more or less abruptly to the plane of the disc, while the innersurface 27 thereof slopes gradually inwardly toward the flat centralportion of surface 22. The ridge is preferably made concentric totrailing edge 24 and, as is evident from FIGURE 2, subtends an angle atof about and is substantially symmetric about that radius of disc 19which is perpendicular to axis of rotation xx.

When the disc member occupies the partially open position of FIGURE 1,surface 27 is inclined more steeply to axis o0 than is the flat portionof surface 22. A stream of inflowing liquid fuel 28 impinges uponsurface 27 and is thence deflected onto wall 12 at the critical depositarea in and about the intersection of plane a-a' with wall 12 andcontiguous to ridge 25. It will be seen that in the absence of suchraised annular ridge, the stream of fuel would be deflected onto wall 12a substantial distance below the critical deposit area.

In FIGURES 3 and 4, there is shown an alternate construction of athrottle disc where in the raised annular ridge is concentric with theperipheral edge of the disc and extends 360 therearound. A throttledisc, indicated generally at 29, is attached to rotary shaft 30 by meansof screws 31. The leading edge of the disc is indicated by numeral 33and the trailing edge thereof by numeral 34. A circular ridge 35 isformed in the upstream surface of disc 29 near the peripheral edgethereof. Ridge 35 is set back a short distance from the peripheral edge.

The outer surface 36 of the ridge is inclined more or less abruptly tothe plane of the disc, while the inner surface 37 thereof slopesgradually inwardly toward the flat central upstream portion of the disc.Although that portion of ridge 35 which is coextensive with leading edge33of disc 29 does not accomplish any fluid-deflecting function, thisconstruction of the disc may be simpler and less expensive tomanufacture than the several embodiments of the disc herein describedwherein the ridge subtends an arc of less than 360.

In FIGURES 5 and 6, there is shown another construction of a throttledisc wherein the raised annular ridge is formed not by machining orcasting the upstream surface of the disc, but rather by machine stampingan A throttle disc 39 is secured to rotary shaft 49 by screws 41. Theleading edge of the disc is indicated by numeral 43 and the trailingedge thereof by numeral 44. A raised annular ridge 45 is formed bybending the undersurface of the disc 39 upwardly to provide ahump-shaped protuberance. The outer surface 46 of ridge 45 is inclinedsteeply to the plane of the disc, while the inner surface 47 thereofslopes gradually inwardly toward the fiat central portion of theupstream surface of disc 39. The ridge is substantially concentric tothe trailing edge 44, subtends an angle of about 90, and is positionedapproximately opposite rotary shaft 40.

In FIGURES 7 and 8, there is illustrated still another embodiment of thethrottle disc wherein theannular ridge is formed by attaching a'beveledring segment to the upstream surface of the disc. The throttle disc,indicated carburetor.

' generallyat 49, is attached to rotary shaft 50 by means 'slopegradually radially inward toward the center of the disc. Ring 55 isformed and positioned so as to be substantially concentric to trailingedge 54 and subtends a central angle of about 90.

The annular ridge of the foregoing embodiments has been shown to subtendan angle of 90 or 360; however, it is not intended to limit itsconstruction to these angles, provided only that the minimum angle be atleast Optimum sizes for particular applications may call for anglesranging from 20 to 360 or preferably from about 60 to about 180. Thephysical dimensions of the fluid-deflecting surface are subject toconsiderable variation and should be established in individual cases inaccordance with the flow characteristic of a particular Throttle bladesof automotive carburetors conventionally range in diameter from about 1/2 inches to about 2 /8 inches; by way of example only, an annular ridgesuitable for blades of such diameters may have a height above the flatupstream surface of the blades of from about 0.05 inch to about 0.20inch; the highest point of the ridge may be set back from the trailingedge of the blade, or more generally from the peripheral edge thereof, adistance of from about 0.05 inch to about 0.30 inch.

Although the foregoing discussion has been directed to throttle bladeshaving the form of a circular or elliptical disc, it is contemplatedthat the present invention is applicable to other shapes to throttleblades such as those which are square, rectangular, hexagonal,octagona1,-etc. The invention may also be employed with throttle bladeswhich are pivoted at one end thereof instead of being rotatably mountedat the center, and may also be used with a valve plug member which ismovable longitudinally in respect of a valve seat Whose transversecross-sectional area varies with longitudinal distance therethrough.

A carburetor throttle valve constructed in accordance with thisinvention will prevent or retard to a substan- 1 the wall of said casingto vary the flow therethrough, and

tial extent the formation of harmful deposits in the critical 7 depositarea as-hereinabove defined. Not only does the instant throttle valveimprove the effectiveness of gasoline detergents in removing dust,grease and gum, but also promotes the action of deicing additives incombating carburetor icing which also generally occurs in the criticaldeposit area.

I claim as my invention:

1. A carburetor throttle valve assembly comprising a casing having afluid inlet opening and a fluid outlet opening'at opposite ends thereof,a movable flow-obstructing member mounted within said casing andcooperable with the Wall of said casing to vary the flow therethrough,and a fluid-deflecting means comprising a raised ridge adjacent to andset back a short distance from the outer edge of said flow-obstructingmember, the inner surface of said ridge being gradually inclined towardthe central portion of said member and the outer surface of the ridgebeing inclined more abruptly toward the plane of said member whereby todeflect impinging fluid, when said flow-obstructing member is in aposition intermediate its fully closed and fully opened positions,against that region of the interior surface of the casing which isadjacent said flow-obstructing member when the latter is in its fullyclosed position.

i 2. A carburetor throttle valve assembly comprising a casing having afluid inlet opening and a fluid outlet opening at opposite ends thereof,a rotatable flow-obstructing the upstream surface of saidflow-obstructing member comprising a raised ridge adjacent to and setback a short distance from the outer edge of said member, the innersurface of said ridge being gradually inclined toward the centralportion of said member and the outer surface of the ridge being inclinedmore abruptly toward the plane of said member whereby to deflectimpinging fluid, when said flow-obstructing member is in a positionintermediate its fully closed and fully opened positions, against thatregion of the interior surface of the casing which is contiguous to thenormally downstream portion of said flowobstructing member when thelatter is in its fully closed position.

3. A carburetor throttle valve assembly comprising a casing having acylindrical bore defining a fluid inlet opening and a fluid outletopening at opposite ends thereof, a rotatable flow-obstructing discmember mounted within said casing and cooperable with the wall of saidcasing to vary the flow therethrough, means for rotating said discmember about an axis substantially perpendicular to and intersecting thecentral longitudinal axis of said casing, and the upstream surface ofsaid disc member comprising a raised ridge portion adjacent to and setback a short distance from the peripheral edge of said disc member, theinner surface of said ridge portion being gradually inclined toward thecentral portion of the disc member and the outer surface of the ridgeportion sloping more abruptly toward the plane of the disc memberwhereby to deflect impinging fluid, when said disc member is in aposition intermediate its fully closed and fully opened positions,against that region of the interior surface of the casing which iscontiguous to the trailing edge of said disc member when the latter isin its fully closed position.

4. A carburetor throttle valve assembly comprising a casing having acylindrical bore defining a fluid inlet opening and a fluid outletopening at opposite ends thereof, a rotatable flow-obstructing discmember mounted within said casing and cooperable with the wall of saidcasing to vary the flow therethrough, shaft means for rotating said discmember about an axis substantially perpendicular to and intersecting thecentral longitudinal axis of said casing, and the upstream surface ofsaid disc member having a raised ridge portion near but set back a shortdistance from the trailing edge of the disc member and subtending anangle of at least 20 measured from the center of the disc member, theinner surface of said ridge portion sloping gradually inwardlyv towardthe flat central portion of the upstream surface of the disc member andthe outer surface of the ridge portion sloping more abruptly toward theplane of the disc member.

5. The apparatus of claim 4 further characterized in that said ridgeportion subtends an angle of approximately measured from the center ofsaid disc member.

6. The apparatus of claim 4 further characterized in that said ridgeportion is substantially parallel to the peripheral edge of said discmember and extends 360 therearound.

References Cited by the Examiner UNITED STATES PATENTS 1,885,331 11/32Collins 261-64 2,095,263 10/37 Moss 251283 2,278,421 4/42 Brown 251305XR 2,322,195 6/43 Mock 251-283 XR 2,436,319 2/48 Meyer 261-65 XR FOREIGNPATENTS 757,030 12/33 France.

1,233,654 10/60 France.

ISADOR WEIL, Primary Examiner.

M. CARY NELSON, Examiner.

1. A CARBURETOR THROTTLE VALVE ASSEMBLY COMPRISING A CASING HAVING AFLUID INLET OPENING AND A FLUID OUTLET OPENING AT OPPOSITE ENDS THEREOF,A MOVABLE FLOW-OBSTRUCTING MEMBER MOUNTED WITH IN SAID CASING ANDCOOPERABLE WITH THE WALL OF SAID CASING TO VARY THE FLOW THERETHROUGH,AND A FLUID-DEFLECTING MEANS COMPRISING A RAISED RIDGE ADJACENT TO ANDSET BACK A SHORT DISTANCE FROM THE OUTER EDGE OF SAID FLOW-OBSTRUCTINGMEMBER, THE INNER SURFACE OF SAID RIDGE BEING GRADUALLY INCLINED TOWARDTHE CENTRAL PORTION OF SAID MEMBER AND THE OUTER SURFACE OF THE RIDGEBEING INCLINED MORE ABRUPTLY TOWARD THE PLANE OF SAID MEMBER WHEREBY TODEFLECT IMPINGING FLUID, WHEN SAID FLOW-OBSTRUCTING MEMBER IS IN APOSITION INTERMEDIATE ITS FULLY CLOSED AND FULLY OPENED POSITIONS,AGAINST THAT REGION OF THE INTERIOR SURFACE OF THE CASING WHICH ISADJACENT SAID FLOW-OBSTRUCTING MEMBER WHEN THE LATTER IS IN ITS FULLYCLOSED POSITION.